During a recent 4-month period we studied two patients who died shortly after operative "repair" of either tetralogy of Fallot (TF) or double-outlet right ventricle (RV), both with subpulmonic obstruction, and necropsy in each disclosed that a major epicardial coronary artery had been inadvertently severed at operation. Because neither patient had had coronary angiography preoperatively and because death in each appeared to resulted from transection of a major coronary artery, a discussion of the rationale for coronary angiography before operative "correction" of complex congenital heart disease appeared warranted.